14. Billingsley's Translated Edition

In 1570, Sir Henry Billingsley first published an edition of Euclid in the English language, 928 pages long, with copious notes and references to other mathematicians, "the first and most important translation" into English, according to Sir Thomas Heath. It had pop-up paper cut-outs in the section on solid figures (Heath, The Thirteen Books of the Elements, 109)

Notice the error on the title page, "Euclid of Megara." Euclid of Megara was an Athenian philosopher who lived at almost the same time as Euclid the mathematician. He was a friend of Plato and was present at the execution of Socrates. The confusion between the two can be seen in several of the photocopies of early printed editions and it was not cleared up until 1572 by an Italian scholar. The confusion is understandable: they were Greek, scholars, and almost contemporaries. They lived, however, on different continents.

Your geometry textbook is a direct descendant of Sir Henry Billingsley's translation.